Hollow charge projectiles

ABSTRACT

A HOLLOW CHARGE PROJECTILE HAVING A PROJECTILE HEAD IN WHICH A CASING IS MOVABLE BETWEEN A POSITION OF REST IN WHICH IT EXTENDS INTO THE INTERIOR OF THE HOLLOW CHARGE AND A WORKING POSITION IN WHICH IT PROTRUDES FROM THE PROJECTILE. A SPRING IS PROVIDED FOR MOVING THE CASING FROM THE POSITION OF REST INTO THE WORKING POSITION. THE SPRING HAS THE SHAPE OF A TRUNCATED CONE WHEREIN THE DIAMETERS OF CONSECUTIVE COILS OF THE SPRING DIFFER BY A LEAST TWICE THE DIAMETER OF THE WIRE. IN THE POSITION OF REST OF THE CASING, THE END OF THE SPRING WITH THE SMALLEST COIL DIAMETER IS DIRECTED TOWARD THE TIP OF A CONICAL CAVITY PROVIDED IN THE HOLLOW CHARGE. THE END OF THE SPRING WITH THE SMALLEST COIL DIAMETER IS FASTENED TO THE CASING AND THE OTHER END OF THE SPRING WITH THE LARGES COIL DIAMETER IS FASTENED TO THE PROJECTILE HEAD.

1971 G. P. L. SCHMINKE HOLLOW CHARGE PROJECTILES Filed Aug. 21, 1969GERHARD P L. flwm/A/L F fl wwzmwmgll m United States atent 3,623,432HOLLOW CHARGE PROJECTILES Gerhard P. L. Schrninke, Opfikon, Switzerland,assignor to Werkzeugmaschinenfabrik Oerlikon-Buhrle AG, Zurich,Switzerland Filed Aug. 21, 1969, Ser. No. 851,808 Claims priority,application Switzerland, Aug. 22, 1968, 127,030/68 Int. Cl. F42c /20 US.Cl. 102-56 2 Claims ABSTRACT OF THE DISCLOSURE A hollow chargeprojectile having a projectile head in which a casing is movable betweena position of rest in which it extends into the interior of the hollowcharge and a working position in which it protrudes from the projectile.A spring is provided for moving the casing from the position of restinto the working position. The spring has the shape of a truncated conewherein the diameters of consecutive coils of the spring differ by atleast twice the diameter of the wire. In the position of rest of thecasing, the end of the spring with the smallest coil diameter isdirected toward the tip of a conical cavity provided in the hollowcharge. The end of the spring with the smallest coil diameter isfastened to the casing and the other end of the spring with the largestcoil diameter is fastened to the projectile head,

The invention relates to a hollow charge projectile, and particularly toa projectile having a projectile head in which a casing is arranged tobe movable, which casing has a position of rest in which it extends intothe interior of the hollow charge, as well as a working position inwhich it protrudes from the projectile, with a spring for shifting thecasing from the position of rest into the working position.

In a known hollow charge projectile of this type, the casing, arrangedcoaxially to the axis of the projectile, is surrounded, on the part ofit which projects into the interior of the hollow charge, by acylindrical spring. One end of the spring is fastened to the rear end ofthe casing, whereas the other end of the spring is fastened to the headof the projectile. In the working position of the casing, the individualcoils of the spring butt one against the other, whereas in the positionof rest of the casing the spring is tensioned. This arrangement has thefollowing disadvantages. The casing can be moved by the spring out ofthe interior of the hollow charge only until the coils of the springbutt one against the other. If the casing has to cover a considerabledistance from the position of rest into the working position, then acylindrical spring with comparatively many coils is required for thisdistance, whereby, in the working position of the casing, acomparatively large part of the casing still projects into the interiorof the hollow charge. Furthermore, the hollow charge effect is disturbedby the cylindrical spring and the part of the casing which projects intothe interior of the hollow charge.

An object of the invention is to avoid or mitigate the aforesaiddisadvantages and to utilise a spring which, with few coils, can movethe casing by a comparatively great distance and at the same time iscapable of moving the casing as completely as possible out of theinterior of the hollow charge.

According to the present invention, there is provided a hollow chargeprojectile, including a projectile head in which a casing is movablebetween a position of rest in which it extends into the interior of thehollow charge and a working position in which it protrudes from theprojectile, and a spring for moving the casing from the position of restinto the working position, wherein the spring has the shape of atruncated cone, and wherein the diameters of consecutive coils of thespring differ by at least twice the diameter of the wire.

One exemplified embodiment of the invention is described in more detailhereinunder with reference to the attached drawings, in which:

FIG. 1 shows a longitudinal section through the front portion of ahollow charge projectile prior to discharge;

FIG. 2 shows a longitudinal section through the front portion of ahollow charge projectile after discharge.

As shown in FIG. 1, inserted into a cylindrical projectile body 1 is afrusto-conical liner 2, whose tip is directed rearwards into theprojectile body 1 coaxially therewith. The projectile body 1 and theliner 2 form an annular space, in which a hollow charge 3 consisting ofexplosive is contained. The projectile body 1 has a shoulder 4 on itsinside. The part 5, lying in front of the shoulder 4, of the projectilebody 1 is thinner-walled than the remaining part 6. A ring 7 is bracedon the shoulder 4. The ring 7 is fastened to the part 6 of theprojectile body 1 by a flanged rim of the part '5. The ring 7 has a rim8 which serves for the centering of the liner 2. A rear front surface 9,perpendicular to the projectile axis, of the ring 7 forms a stop for theliner 2.

The projectile body 1 is terminated in front by a cover 10, designed asa projectile head, which is fastened to the ring 7 by an annularextension piece 11. The cover 10 has a central bore-hole 12, whose axiscoincides with the projectile axis. A casing 13 is mounted to be movablein this bore-hole 12. Fastened to this casing is a second casing 14projecting into the liner 2. The front section of the casing 14 containsa detonator 15. Present on the inner wall of the casing 14 is aring-shaped shoulder 16, against which a front face of the detonator 15butts. In addition, the casing 13 has an inwardly projecting shoulder17, against which a thin sheet disc 18 is pressed by the forward frontface of the casing 14.

A firing pin 19, which has a shaft 20 and a firing pin head 31, isguided movably in the casing 13. The shaft 26 of the firing pin 19 isbraced on the sheet disc 18. The tip of the firing pin 19 extendsthrough the sheet disc 18 into the casing 14 and is in front of thedetonator 15. The shaft 20 of the firing pin 19 butts, in the positionshown, against an inwardly projecting annular shoulder 21 of the casing13. This shoulder 21 prevents the firing pin 19 from being able to fallin front out of the cover 10. The outer side of the casing 13 has agroove of V-shaped cross section which extends in the peripheraldirection. In the cover 10 there is a bore-hole 23 which is directedtransversely to the projectile axis and in which a safety bolt 24 isshiftably mounted. This safety bolt 24 has a conical tip which buttsagainst a wall 30 in the groove 22 of the casing 13. The end 25,opposite to the tip, of the safety bolt 24 butts against a wall 26forming a guide for the projectile.

One end of a draw spring 28, having the shape of a truncated cone, withthe largest coil diameter is fastened in a slot 27 on the inside of thecover extension piece 11, and the other end of the spring 28 with thesmallest coil diameter is fastened to a flange 29 of the casing 14. Thediameters of the consecutive coils of the spring 28 differ by at leasttwice the diameter of the wire. The end of the spring with the smallestcoil diameter projects towards the tip of the conical cavity of thehollow charge 3 when the casing 14 is in its position of rest, and inthe working position of the casing 14 this end projects in the oppositedirection. The coils of the spring 28 in the working position of thecasing 14 lie practically in one plane.

The method of operation is as follows:

After the projectile has moved away from the wall 26, the safety bolt 24is no longer held back. The bolt 24 is therefore driven out from thegroove 22 by the force, acting on the casings 13, 14, of the spring 28,which force is transmitted to the bolts head by the wall 30 of thegroove 22. By this means, the casings 13, 14 containing the firing pin19 and the detonator 15 are released and shifted by the spring 28forward through the cover bore-hole 12 into the position shown in FIG.2. Upon this movement, the coils of the spring 28 fit into each other,i.e telescope, so that finally they lie substantially in one plane andthe rear end of the casing 14 can move as far as the stop of the cover10.

The air pressure head acting on the firing pin head 31 is not sufiicientto punch through the sheet disc 18. However, upon impact in the target,the firing pin 19 is driven backwards into the detonator 15, and thehollow charge 3 is exploded in known manner by means of the detonator 15and a further detonator (not shown in the drawing).

I claim:

1. A projectile with a conical hollow space having a hollow charge,comprising a projectile head, a casing in said projectile head movablefrom a position of rest wherein said casing extends into said hollowcharge to a working position wherein said casing protrudes from saidprojectile head, a truncated cone-shaped spring having a plurality ofconsecutive coils of different diameters wherein the diameters of saidconsecutive coils differ by at least twice the diameter of the wireforming said coils,

said spring being fastened at the end With the smallest coil diameteronto said casing and at the end With the largest coil diameter onto saidprojectile head to urge said casing from the position of rest into saidworking position so that said spring is reversed whereby in the workingposition of said casing the end with the small coil diameter points inthe opposite direction from that in the position of rest of said casing.

2. A projectile as set forth in claim 1 wherein said spring is reversedupon moving said casing to working position and the coils of said springare substantially located in one plane.

References Cited UNITED STATES PATENTS 1,229,669 6/1917 Stuart 102-792,717,552 9/1955 Brandt 10256 2,737,118 3/1956 Peck 102-79 3,3803 844/1968 Kaiser et a1 102-71 VERLIN R. PENDEGRASS, Primary Examiner US.Cl. X.R. 10276

